Revisiting lepton-specific 2HDM in light of muon g − 2 anomaly

Lei Wang,Jin Min Yang,Mengchao Zhang,Yang Zhang

doi:10.1016/j.physletb.2018.11.045

Abstract

We examine the lepton-specific 2HDM as a solution of muon g−2 anomaly under various theoretical and experimental constraints, especially the direct search limits from the LHC and the requirement of a strong first-order phase transition in the early universe. We find that the muon g−2 anomaly can be explained in the region of 32<tan⁡β<80, 10GeV<mA<65GeV, 260GeV<mH<620GeV and 180GeV<mH±<620GeV after imposing the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs data, the leptonic/semi-hadronic τ decays, the leptonic Z decays and Br(Bs→μ+μ−). The direct searches from the h→AA channels can impose stringent upper limits on Br(h→AA) and the multi-lepton event searches can sizably reduce the allowed region of mA and tan⁡β (10GeV<mA<44GeV and 32<tan⁡β<60). Finally, we find that the model can produce a strong first-order phase transition in the region of 14GeV<mA<25GeV, 310GeV<mH<355GeV and 250GeV<mH±<295GeV, allowed by the explanation of the muon g−2 anomaly.

Highlights

The muon anomalous magnetic moment (g − 2) is a very precisely measured observable
In this work we examine the parameter space of lepton-specific 2HDM (L2HDM) by considering the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs signal data, the muon g − 2 anomaly, the lepton flavor universality (LFU) in the τ and Z decays, the measurement of Br(Bs → μ+μ−), as well as the direct search limits from the LHC
The L2HDM can provide a simple explanation for the muon g −2 anomaly

Summary

INTRODUCTION

The muon anomalous magnetic moment (g − 2) is a very precisely measured observable. The muon g − 2 anomaly has been a long-standing puzzle since the announcement by the E821 experiment in 2001 [1, 2]. The observation of Br(Bs → μ+μ−) gives a new constraint on the parameter space of L2HDM [15]. In this work we examine the parameter space of L2HDM by considering the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs signal data, the muon g − 2 anomaly, the lepton flavor universality (LFU) in the τ and Z decays, the measurement of Br(Bs → μ+μ−), as well as the direct search limits from the LHC (the data of some channels analyzed by the ATLAS and CMS are corresponding to an integrated luminosity up to about 36 f b−1 recorded in proton-proton collisions at √s = 13 TeV).

THE LEPTON-SPECIFIC 2HDM

Numerical calculations

Results and discussions

THE DIRECT SEARCH LIMITS FROM THE LHC

THE STRONG FIRST-ORDER PHASE TRANSITION

CONCLUSION